Nitrous oxide, tropospheric

Like methane and nitrous oxide, tropospheric ozone is a natural greenhouse gas, but one which has a short tropospheric residence time. Ozone s bending vibration occurs at 14.2 pm, near that for CO2, and thus it does not contribute much to the enhancement of the greenhouse effect since atmospheric carbon dioxide already removes much of the outgoing light in this wavelength. 

Weiss, R. F. (1981). The temporal and spatial distribution of tropospheric nitrous oxide. /. Geophys. Res. 86, 7185-7195. 

Recent estimates indicate that the level of carbon dioxide in the atmosphere has increased by a third since the beginning of the industrial age, and that it contributes significantly to global warming. Other major contributors include methane, tropospheric ozone, and nitrous oxide. Methane is the principal component of natural gas, but it is also produced by other sources such as rice paddies and farm animals. Tropospheric ozone is generated naturally and by the sunlight-... 

Nitrous oxide (N2O) is an important greenhonse gas with a radiative forcing effect 310 times that of CO2 and a lifetime in the troposphere of approximately 120 years. Part of the N2O is converted to NO in the stratosphere, and so contributes to depletion of ozone. Nitric oxide (NO) is very reactive in the atmosphere and has a lifetime of only 1-10 days. It contribntes to acidification and to reactions leading to the formation of ozone in the troposphere, and so also to global warming. 

Nitrous oxide is important not only as a greenhouse gas but, as discussed in Chapter 12, as the major natural source of NC/ in the stratosphere, where it is transported due to its long tropospheric lifetime (Crutzen, 1970). The major sources of N20 are nitrification and denitrification in soils and aquatic systems, with smaller amounts directly from anthropogenic processes such as sewage treatment and fossil fuel combustion (e.g., see Delwiche, 1981 Khalil and Rasmussen, 1992 Williams et al., 1992 Nevison et al., 1995, 1996 Prasad, 1994, 1997 Bouwman and Taylor, 1996 and Prasad et al., 1997). The use of fertilizers increases N20 emissions. For pastures at least, soil water content at the time of fertilization appears to be an important factor in determining emissions of N20 (and NO) (Veldkamp et al., 1998). 

Gases, such as water vapor, carbon dioxide, tropospheric ozone, nitrous oxide, methane, and chloroflurocarbons (CFCs), are largely transparent to solar radiation... 

In this case, N20 (called nitrous oxide or laughing gas) has natural sources, such as emissions from swamps and other oxygen-free ( anoxic ) waters and soils. The oxygen atoms in this reaction can come from several tropospheric photolytic reactions involving OH or OOH. Another source of NO is the thermal reaction between N2 and 02 ... 

Nitrous oxide (N20) is produced by bacteria in the natural denitrification process. It is chemically inert in the troposphere, but in the stratosphere it is degraded photochemically. The average concentration of N20 in the troposphere is about 300 ppb, and its residence time there is 10 years. What is the global rate of production of N20 in units of kg/ year Assume that the volume of the stratosphere (at 0°C and 1 atm) is 10% that of the atmosphere. 

The temperature and density structure of the troposphere, along with the concentrations of major constituents, are well documented and altitude profiles have been measured over a wide range of seasons and latitudes for the minor species water, carbon dioxide, and ozone. A few profiles are available for carbon monoxide, nitrous oxide, methane, and molecular hydrogen, while only surface or low-altitude measurements have been made for nitric oxide, nitrogen dioxide, ammonia, sulfur dioxide, hydrogen sulfide, and nonmethane hydrocarbons. No direct measurements of nitric acid and formaldehyde are available, though indirect information does exist. The concentrations of a number of other important species, such as peroxides and oxy and peroxy radicals, have never been determined. Therefore, while considerable information concerning trace constituent concentrations is available, the picture is far from complete. 

For the major atmospheric oxide of nitrogen—nitrous oxide—the source is biological activity at the surface, and the sink is transport into the stratosphere, where it is destroyed by photodissociation and reaction with 0( D). There are no important photochemical reactions for nitrous oxide in the troposphere. 

The last step in the current manufacture of adipic acid involves oxidation by nitric acid, which results in the formation of nitrous oxide (N2O) that is released into the atmosphere. Given that N2O has no tropospheric sinks, it can rise to the stratosphere and be a factor in the destruction of the ozone layer. It also acts as a greenhouse gas (see Section 8.4.1). 

Globally, the oxides of nitrogen, NO (nitric oxide), NO2 (nitrogen oxide), and N2O (nitrous oxide), are key species involved in the chemistry of the troposphere and stratosphere. NO and N2O are produced mostly by microbial soil activity, whereas biomass burning is also an important source of NO. Nitric oxide is a species involved in the photochemical production of ozone in the troposphere, is involved in the chemical produaion of nitric acid, and is an important component of acid precipitation. Nitrous oxide plays a key role in stratospheric ozone depletion and is an important greenhouse gas, with a global warming potential more than 200 times that of CO2. 

You mentioned the reaction between oxygen and nitrous oxide. Most environmental chemists pay attention to NO and NO2 as well as their interconversion, but little attention is paid to N2O. Does N2O have a part in the nitrogen cycle We are very curious about the fact that it is present uniformly in the troposphere at about 0.25 ppm. Is the reaction of oxygen and of direct relevance to the atmosphere ... 

Alyea F.N., CuNNOLD D.M. and Prinn R.G., Meteorological constraints on tropospheric halocarbon and nitrous oxide destruction by siliceous land surfaces. Atmos. Environ. , 12, 1009-1015 (1978). 

Nitric oxide (NO), nitrous oxide (N2O), dinitrogen (N2), and ammonia (NH3) are constituents of the Earth s atmosphere. They play important roles in the chemistry and climate of the present-day Earth. Moreover, they are intermediates of the oceanic nitrogen cycle. In contrast to most of the other components of the oceanic nitrogen cycle, they exist as dissolved gaseous molecules. Being gases they can be transferred across the seasurface-troposphere interface. 

Kaiser, J., Rockmann, T., and Brenninkmeijer, C. A. M. (2003). Complete and accurate mass spectrometric isotope analysis of tropospheric nitrous oxide. J. Geophys. Res. 108(D15), 4476, doi 10.1029/2003JD003613. 

Nitrous oxide (N20), another greenhouse gas, is stable in the troposphere, but oxidizes to ozone-reactive NO in the stratosphere. Molecule for molecule, N20 is currently about 200 times more effective in absorbing long-wave infrared radiation than is carbon dioxide, and its atmospheric concentration... 

Here we can see a biological source for nitrous oxide (N20), an important and rather stable trace gas in the troposphere. In nature there are many other... 

A ground level source, and stratospheric sink for N2O, is consistent with the observed vertical concentration gradient. McElroy et al. (1976) estimate that an ozone reduction of up to 20% is possible, based upon the above catalytic cycle and increasing anthropogenic emissions of N2O, assuming no other sinks for atmospheric nitrous oxide are found. More recent model predictions suggest a total column ozone reduction of 4% based on the current increase in tropospheric N2O concentrations (National Research Council, 1984). 

Pierotti, D., R. A. Rasmussen, and R. Chatfield (1978). Continuous measurements of nitrous oxide in the troposphere. Nature 274, 574-576. 

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